Kurds' success is not quite that simple, Dave. Since the first Gulf war, the US has been supplying them with virtually anything they desire--and guaranteeing their security against Saddam. Not entirely for altruistic reasons--"Kurdistan", amply supplied with oil, is the the US fall-back position for oil if the rest of Iraq turns completely hostile.

However there's also a sizable downside now to "Kurdistan"'s" de facto independence. It's gone so far now that the Iraqi flag is banned there--only the Kurdish flag. And they threaten de jure independence if the Baghdad government tries to revoke the oil deals they have made-- made without the approval of that government.

So basically "Kurdistan" is no longer part of Iraq--it was actually added in the 20's artificially anyway--to try to balance the Shiite majority.

And the question becomes: how far will the Shiite south seek to emulate this?